/* -*- Mode: C; c-basic-offset:4 ; -*- */
/*
 *  (C) 2003 by Argonne National Laboratory.
 *      See COPYRIGHT in top-level directory.
 */
#include "mpi.h"
#include <stdio.h>
#include <stdlib.h>
#include "mpitest.h"

/*
static char MTEST_Descrip[] = "Test of various send cancel calls";
*/

int main( int argc, char *argv[] )
{
    int errs = 0;
    int rank, size, source, dest;
    MPI_Comm      comm;
    MPI_Status    status;
    MPI_Request   req;
    static int bufsizes[4] = { 1, 100, 10000, 1000000 };
    char *buf;
    int  cs, flag, n;
#ifdef TEST_IRSEND
    int veryPicky = 0;   /* Set to 1 to test "quality of implementation" in
			    a tricky part of cancel */
#endif

    MTest_Init( &argc, &argv );

    comm = MPI_COMM_WORLD;
    MPI_Comm_rank( comm, &rank );
    MPI_Comm_size( comm, &size );

    source = 0;
    dest   = size - 1;

    for (cs=0; cs<4; cs++) {
	if (rank == 0) {
	    n = bufsizes[cs];
	    buf = (char *)malloc( n );
	    if (!buf) {
		fprintf( stderr, "Unable to allocate %d bytes\n", n );
		MPI_Abort( MPI_COMM_WORLD, 1 );
	    }
	    MPI_Send_init( buf, n, MPI_CHAR, dest, cs+n+1, comm, &req );
	    MPI_Start( &req );
	    MPI_Cancel( &req );
	    MPI_Wait( &req, &status );
	    MPI_Test_cancelled( &status, &flag );
	    if (!flag) {
		errs ++;
		printf( "Failed to cancel a persistent send request\n" );
		fflush(stdout);
	    }
	    else
	    {
		n = 0;
	    }
	    MPI_Request_free( &req );
	    /* Send the size, zero for successfully cancelled */
	    MPI_Send( &n, 1, MPI_INT, dest, 123, comm );
	    /* Send the tag so the message can be received */
	    n = cs+n+1;
	    MPI_Send( &n, 1, MPI_INT, dest, 123, comm );
	    free( buf );
	}
	else if (rank == dest)
	{
	    int nn, tag;
	    char *btemp;
	    MPI_Recv( &nn, 1, MPI_INT, 0, 123, comm, &status );
	    MPI_Recv( &tag, 1, MPI_INT, 0, 123, comm, &status );
	    if (nn > 0)
	    {
		/* If the message was not cancelled, receive it here */
		btemp = (char*)malloc( nn );
		if (!btemp)
		{
		    fprintf( stderr, "Unable to allocate %d bytes\n", nn);
		    MPI_Abort( MPI_COMM_WORLD, 1 );
		}
		MPI_Recv( btemp, nn, MPI_CHAR, 0, tag, comm, &status );
		free(btemp);
	    }
	}
	MPI_Barrier( comm );

	if (rank == 0) {
	    char *bsendbuf;
	    int bsendbufsize;
	    int bf, bs;
	    n = bufsizes[cs];
	    buf = (char *)malloc( n );
	    if (!buf) {
		fprintf( stderr, "Unable to allocate %d bytes\n", n );
		MPI_Abort( MPI_COMM_WORLD, 1 );
	    }
	    bsendbufsize = n + MPI_BSEND_OVERHEAD;
	    bsendbuf = (char *)malloc( bsendbufsize );
	    if (!bsendbuf) {
		fprintf( stderr, "Unable to allocate %d bytes for bsend\n", n );
		MPI_Abort( MPI_COMM_WORLD, 1 );
	    }
	    MPI_Buffer_attach( bsendbuf, bsendbufsize );
	    MPI_Bsend_init( buf, n, MPI_CHAR, dest, cs+n+2, comm, &req );
	    MPI_Start( &req );
	    MPI_Cancel( &req );
	    MPI_Wait( &req, &status );
	    MPI_Test_cancelled( &status, &flag );
	    if (!flag) {
		errs ++;
		printf( "Failed to cancel a persistent bsend request\n" );
		fflush(stdout);
	    }
	    else
	    {
		n = 0;
	    }
	    MPI_Request_free( &req );
	    /* Send the size, zero for successfully cancelled */
	    MPI_Send( &n, 1, MPI_INT, dest, 123, comm );
	    /* Send the tag so the message can be received */
	    n = cs+n+2;
	    MPI_Send( &n, 1, MPI_INT, dest, 123, comm );
	    free( buf );
	    MPI_Buffer_detach( &bf, &bs );
	    free( bsendbuf );
	}
	else if (rank == dest)
	{
	    int nn, tag;
	    char *btemp;
	    MPI_Recv( &nn, 1, MPI_INT, 0, 123, comm, &status );
	    MPI_Recv( &tag, 1, MPI_INT, 0, 123, comm, &status );
	    if (nn > 0)
	    {
		/* If the message was not cancelled, receive it here */
		btemp = (char*)malloc( nn );
		if (!btemp)
		{
		    fprintf( stderr, "Unable to allocate %d bytes\n", nn);
		    MPI_Abort( MPI_COMM_WORLD, 1 );
		}
		MPI_Recv( btemp, nn, MPI_CHAR, 0, tag, comm, &status );
		free(btemp);
	    }
	}
	MPI_Barrier( comm );

	/* Because this test is erroneous, we do not perform it unless
	   TEST_IRSEND is defined.  */
#ifdef TEST_IRSEND
	/* We avoid ready send to self because an implementation
	   is free to detect the error in delivering a message to
	   itself without a pending receive; we could also check
	   for an error return from the MPI_Irsend */
	if (rank == 0 && dest != rank) {
	    n = bufsizes[cs];
	    buf = (char *)malloc( n );
	    if (!buf) {
		fprintf( stderr, "Unable to allocate %d bytes\n", n );
		MPI_Abort( MPI_COMM_WORLD, 1 );
	    }
	    MPI_Rsend_init( buf, n, MPI_CHAR, dest, cs+n+3, comm, &req );
	    MPI_Start( &req );
	    MPI_Cancel( &req );
	    MPI_Wait( &req, &status );
	    MPI_Test_cancelled( &status, &flag );
	    /* This can be pretty ugly.  The standard is clear (Section 3.8)
	       that either a sent message is received or the 
	       sent message is successfully cancelled.  Since this message
	       can never be received, the cancel must complete
	       successfully.  

	       However, since there is no matching receive, this
	       program is erroneous.  In this case, we can't really
	       flag this as an error */
	    if (!flag && veryPicky) {
		errs ++;
		printf( "Failed to cancel a persistent rsend request\n" );
		fflush(stdout);
	    }
	    if (flag)
	    {
		n = 0;
	    }
	    MPI_Request_free( &req );
	    /* Send the size, zero for successfully cancelled */
	    MPI_Send( &n, 1, MPI_INT, dest, 123, comm );
	    /* Send the tag so the message can be received */
	    n = cs+n+3;
	    MPI_Send( &n, 1, MPI_INT, dest, 123, comm );
	    free( buf );
	}
	else if (rank == dest)
	{
	    int n, tag;
	    char *btemp;
	    MPI_Recv( &n, 1, MPI_INT, 0, 123, comm, &status );
	    MPI_Recv( &tag, 1, MPI_INT, 0, 123, comm, &status );
	    if (n > 0)
	    {
		/* If the message was not cancelled, receive it here */
		btemp = (char*)malloc( n );
		if (!btemp)
		{
		    fprintf( stderr, "Unable to allocate %d bytes\n", n);
		    MPI_Abort( MPI_COMM_WORLD, 1 );
		}
		MPI_Recv( btemp, n, MPI_CHAR, 0, tag, comm, &status );
		free(btemp);
	    }
	}
	MPI_Barrier( comm );
#endif

	if (rank == 0) {
	    n = bufsizes[cs];
	    buf = (char *)malloc( n );
	    if (!buf) {
		fprintf( stderr, "Unable to allocate %d bytes\n", n );
		MPI_Abort( MPI_COMM_WORLD, 1 );
	    }
	    MPI_Ssend_init( buf, n, MPI_CHAR, dest, cs+n+4, comm, &req );
	    MPI_Start( &req );
	    MPI_Cancel( &req );
	    MPI_Wait( &req, &status );
	    MPI_Test_cancelled( &status, &flag );
	    if (!flag) {
		errs ++;
		printf( "Failed to cancel a persistent ssend request\n" );
		fflush(stdout);
	    }
	    else
	    {
		n = 0;
	    }
	    MPI_Request_free( &req );
	    /* Send the size, zero for successfully cancelled */
	    MPI_Send( &n, 1, MPI_INT, dest, 123, comm );
	    /* Send the tag so the message can be received */
	    n = cs+n+4;
	    MPI_Send( &n, 1, MPI_INT, dest, 123, comm );
	    free( buf );
	}
	else if (rank == dest)
	{
	    int nn, tag;
	    char *btemp;
	    MPI_Recv( &nn, 1, MPI_INT, 0, 123, comm, &status );
	    MPI_Recv( &tag, 1, MPI_INT, 0, 123, comm, &status );
	    if (nn > 0)
	    {
		/* If the message was not cancelled, receive it here */
		btemp = (char*)malloc( nn );
		if (!btemp)
		{
		    fprintf( stderr, "Unable to allocate %d bytes\n", nn);
		    MPI_Abort( MPI_COMM_WORLD, 1 );
		}
		MPI_Recv( btemp, nn, MPI_CHAR, 0, tag, comm, &status );
		free(btemp);
	    }
	}
	MPI_Barrier( comm );
    }

    MTest_Finalize( errs );
    MPI_Finalize();
    return 0;
}
